This invention relates to an apparatus for removing products from an injection mold or for placing product parts in an injection mold.
Such an apparatus is described, for instance, in EP-B-0 415 153. The know apparatus comprises a receiving element mounted on the free end of a swivelling arm which is connected through its other end to a rotary shaft which is fixedly connected to a first mold part. The swivelling position of the swivelling arm is controlled by means of a curve mechanism, of which the curve is connected to the second mold part and the curve follower is connected to the rotary shaft via a track and pinion. The advantage of this way of controlling the swivelling position of the swivelling arm is that the total path to be traversed by the receiving element takes place during the cycle of the opening and closure of the mold parts.
Accordingly, relative to the mold part to which the rotary shaft is connected, the receiving element can only traverse a simple circular path. The position of the receiving element, which is constructed as a suction cup in the known apparatus, relative to the swivelling arm is always the same. A first drawback is therefore that the possible positions and orientation in which the product to be removed can be delivered are very limited.
Owing to the movement of the receiving element being only a swivelling movement, products with a higher profile, such as, for instance, buckets, cannot be taken from the mold using the known apparatus, since the path of the product is an arc of a circle, which makes it impossible to slide the product off the core. Moreover there is a possibility that the product cannot be moved from between the two mold parts when only a path describing an arc of a circle can be traversed. A second drawback is therefore that the path of movement of the product to be removed cannot be chosen freely.
A third drawback of the known apparatus is that after the mold parts have been closed, the receiving element cannot be displaced further because the rotary shaft of the swivelling arm is fixedly connected to the mold. As a result, there is no possibility of further maneuvering of the product without transferring it to a further positioning device. The drawback of transferring the products to further positioning devices is that the position of the products may be disturbed during transfer.
The apparatus which is described in U.S. Pat. No. 3,700,375 also has the above-described drawbacks. The receiving element in this known apparatus is connected via a parallelogram linkage to a rotary shaft which is fixedly arranged with respect to one of the mold parts. In this known apparatus too the receiving element moves along a simple arc of a circle with respect to the mold part to which the rotary shaft is connected. Accordingly, the product to be removed moves along a fixed path which cannot be chosen freely and the range of possibilities with regard to the position and the orientation of the product in the delivery position is also very limited. It moreover holds for this apparatus too that after the mold parts have been closed, the receiving element cannot be moved any further because the rotary shaft of the swivelling arm is fixedly connected to the mold.